Telecommunication, one of the indispensable elements of our era, is realized and developed with many different methods and aims. Except the communication devices such as television, cellular phone which are used frequently, radio networks which the public security officers use and which are based on the ground of wireless communication are still being developed and widely used. The communication performed through the analogue channels which used to be selected manually with the said radio devices and networks has been developed until today and systems based on digital data communication are established wherein more than one radio can communicate through a single channel via trunked radio systems. Trunked radio system is one of these which are most commonly used.
Today analogue radio systems are still used, but it loses its generality because it cannot meet the needs in some cases. For example, when the locations of the radios in the network are desired to be found swiftly, the locations are required to be learnt vocally one by one by communicating with each radio since the analogue systems are not suitable for data communication. In this case, the possibility that there is no person to answer any time at each station makes difficult to learn the locations of the devices. In order to make this process easy, systems which gives approximate information with shared analysis of the distance mobile radio device to the certain stations by measuring the signal intensity have been developed, however a more modern technique wherein the radio on which a global positioning system is located developed only for this process informs about the location through a digital data channel has gone beyond the said method. GPS (Global Positioning System) can be shown as an example of the said systems. GPS modules can determine the location of the GPS receiver accurately by performing time correction generally from a fourth satellite according to the signal durations it receives from the satellites, and reports as latitude, longitude and height information.
In radio systems having digital data communication, the data are sent directly or indirectly to the receiver in packages through the various channel units with constant or variable frequency and reach the right terminal/station targeted. FDMA (or Frequency Division Multiple Access). TIA-102 can be shown as example for the said communication platforms. For example TSBK (Trunking Signalling Block) is used for data communication. An exemplary TSBK is shown in Table 1.
TABLE 1Octet 0LBPOpcodeOctet 1(Manufacturer's ID)Octet 2Parameters(Arguments)Octet 3Octet 4Octet 5Octet 6Octet 7Octet 8Octet 9Octet 10TSBKOctet 11CRCBit76543210
The radio modules, used today and having a GPS receiver thereon, uses various methods to transfer the location information received from the GPS. Again, performing data communication through standard platforms developed for trunked radio systems provides advantage in sending the said data. In this kind of communication systems during sending the global location information periodically (active) or upon the demand of the system (passive), the data are acquired either from the same channel or another determined channel. When such system is used, in location information transmission performed periodically from the terminal or the subscribers, collisions occur relating to GPS data acquiring from a plurality of radios; enough coordinate information in desired timing cannot be acquired from the system. In sending GPS upon request (passive) technique, data channel request messages of the radios may collide with any vocal or the like service request message of other radios, and this cause both the GPS data acquiring process to hinder and delays in other services getting service.
Today, in FDMA Digital Communication systems, during GPS data query from the radio/radios actively, generally the radio changes the channel after receiving the query, informs the other party performing messaging such as “arrived in channel” and “ready”, then sends GPS data, returns to the channel where it is waiting and sends another message about ending the process. When the steps of the said system are followed, many channel changes are required, location query durations extend and radio channels (for example traffic channel) are kept busy unnecessarily. Besides, data can be requested/questioned only from one radio once with the current technique and the same process is repeated for all radios separately.
International patent document no WO 1998048294, an application known in the state of the art, discloses a positioning system which determines the location of a mobile device by using differences of the signal time of arrival received by at least one positioning radio receiver and originating from the signal detection speeds of the components within the said devices.
Chinese patent document no CN101478729 discloses a method which realizes the GPS positioning of mobile terminal with MPT-1327 trunking communication and acquires the data coming from the GPS module at the mobile terminal with the data communication realized actively and passively through the control and traffic channels by processing in the system.
Korean patent document no KR20070006127, an application known in the state of the art, discloses a geographical information providing method which transmits the customer information to the taxi by finding the closest taxi to the customer with the aim of providing convenience for the customer, and acquires these in a storage device and uses trunked radio systems.